forked from lijiext/lammps
272 lines
13 KiB
HTML
272 lines
13 KiB
HTML
|
|
|
|
<!DOCTYPE html>
|
|
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
|
|
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
|
|
<head>
|
|
<meta charset="utf-8">
|
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
|
|
<title>fix nve/manifold/rattle command — LAMMPS documentation</title>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
|
|
|
|
|
|
|
|
<link rel="stylesheet" href="_static/sphinxcontrib-images/LightBox2/lightbox2/css/lightbox.css" type="text/css" />
|
|
|
|
|
|
|
|
<link rel="top" title="LAMMPS documentation" href="index.html"/>
|
|
|
|
|
|
<script src="_static/js/modernizr.min.js"></script>
|
|
|
|
</head>
|
|
|
|
<body class="wy-body-for-nav" role="document">
|
|
|
|
<div class="wy-grid-for-nav">
|
|
|
|
|
|
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
|
|
<div class="wy-side-nav-search">
|
|
|
|
|
|
|
|
<a href="Manual.html" class="icon icon-home"> LAMMPS
|
|
|
|
|
|
|
|
</a>
|
|
|
|
|
|
<div role="search">
|
|
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
|
|
<input type="text" name="q" placeholder="Search docs" />
|
|
<input type="hidden" name="check_keywords" value="yes" />
|
|
<input type="hidden" name="area" value="default" />
|
|
</form>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
|
|
|
|
|
|
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_intro.html">1. Introduction</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_start.html">2. Getting Started</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_commands.html">3. Commands</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_packages.html">4. Packages</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_accelerate.html">5. Accelerating LAMMPS performance</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_howto.html">6. How-to discussions</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_example.html">7. Example problems</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_perf.html">8. Performance & scalability</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_tools.html">9. Additional tools</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_modify.html">10. Modifying & extending LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_python.html">11. Python interface to LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_errors.html">12. Errors</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_history.html">13. Future and history</a></li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</nav>
|
|
|
|
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
|
|
|
|
|
|
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
|
|
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
|
|
<a href="Manual.html">LAMMPS</a>
|
|
</nav>
|
|
|
|
|
|
|
|
<div class="wy-nav-content">
|
|
<div class="rst-content">
|
|
<div role="navigation" aria-label="breadcrumbs navigation">
|
|
<ul class="wy-breadcrumbs">
|
|
<li><a href="Manual.html">Docs</a> »</li>
|
|
|
|
<li>fix nve/manifold/rattle command</li>
|
|
<li class="wy-breadcrumbs-aside">
|
|
|
|
|
|
<a href="http://lammps.sandia.gov">Website</a>
|
|
<a href="Section_commands.html#comm">Commands</a>
|
|
|
|
</li>
|
|
</ul>
|
|
<hr/>
|
|
|
|
</div>
|
|
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
|
|
<div itemprop="articleBody">
|
|
|
|
<div class="section" id="fix-nve-manifold-rattle-command">
|
|
<span id="index-0"></span><h1>fix nve/manifold/rattle command</h1>
|
|
<div class="section" id="syntax">
|
|
<h2>Syntax</h2>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">nve</span><span class="o">/</span><span class="n">manifold</span><span class="o">/</span><span class="n">rattle</span> <span class="n">tol</span> <span class="n">maxit</span> <span class="n">manifold</span> <span class="n">manifold</span><span class="o">-</span><span class="n">args</span> <span class="n">keyword</span> <span class="n">value</span> <span class="o">...</span>
|
|
</pre></div>
|
|
</div>
|
|
<ul class="simple">
|
|
<li>ID, group-ID are documented in <a class="reference internal" href="fix.html"><span class="doc">fix</span></a> command</li>
|
|
<li>nve/manifold/rattle = style name of this fix command</li>
|
|
<li>tol = tolerance to which Newton iteration must converge</li>
|
|
<li>maxit = maximum number of iterations to perform</li>
|
|
<li>manifold = name of the manifold</li>
|
|
<li>manifold-args = parameters for the manifold</li>
|
|
<li>one or more keyword/value pairs may be appended</li>
|
|
</ul>
|
|
<pre class="literal-block">
|
|
keyword = <em>every</em>
|
|
<em>every</em> values = N
|
|
N = print info about iteration every N steps. N = 0 means no output
|
|
</pre>
|
|
</div>
|
|
<div class="section" id="examples">
|
|
<h2>Examples</h2>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="mi">1</span> <span class="nb">all</span> <span class="n">nve</span><span class="o">/</span><span class="n">manifold</span><span class="o">/</span><span class="n">rattle</span> <span class="mi">1</span><span class="n">e</span><span class="o">-</span><span class="mi">4</span> <span class="mi">10</span> <span class="n">sphere</span> <span class="mf">5.0</span>
|
|
<span class="n">fix</span> <span class="n">step</span> <span class="nb">all</span> <span class="n">nve</span><span class="o">/</span><span class="n">manifold</span><span class="o">/</span><span class="n">rattle</span> <span class="mi">1</span><span class="n">e</span><span class="o">-</span><span class="mi">8</span> <span class="mi">100</span> <span class="n">ellipsoid</span> <span class="mf">2.5</span> <span class="mf">2.5</span> <span class="mf">5.0</span> <span class="n">every</span> <span class="mi">25</span>
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="description">
|
|
<h2>Description</h2>
|
|
<p>Perform constant NVE integration to update position and velocity for
|
|
atoms constrained to a curved surface (manifold) in the group each timestep. The constraint
|
|
is handled by RATTLE <a class="reference internal" href="fix_shake.html#andersen"><span class="std std-ref">(Andersen)</span></a> written out for the special case of
|
|
single-particle constraints as explained in <a class="reference internal" href="manifolds.html#paquay"><span class="std std-ref">(Paquay)</span></a>.
|
|
V is volume; E is energy. This way, the dynamics of particles constrained to
|
|
curved surfaces can be studied. If combined with <a class="reference internal" href="fix_langevin.html"><span class="doc">fix langevin</span></a>, this generates
|
|
Brownian motion of particles constrained to a curved surface. For a list of currently supported
|
|
manifolds and their parameters, see <a class="reference internal" href="manifolds.html"><span class="doc">manifolds</span></a>.</p>
|
|
<p>Note that the particles must initially be close to the manifold in question. If not, RATTLE will
|
|
not be able to iterate until the constraint is satisfied, and an error is generated. For simple
|
|
manifolds this can be achieved with <em>region</em> and <em>create_atoms</em> commands, but for more complex
|
|
surfaces it might be more useful to write a script.</p>
|
|
<p>The manifold args may be equal-style variables, like so:</p>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">variable</span> <span class="n">R</span> <span class="n">equal</span> <span class="s2">"ramp(5.0,3.0)"</span>
|
|
<span class="n">fix</span> <span class="n">shrink_sphere</span> <span class="nb">all</span> <span class="n">nve</span><span class="o">/</span><span class="n">manifold</span><span class="o">/</span><span class="n">rattle</span> <span class="mi">1</span><span class="n">e</span><span class="o">-</span><span class="mi">4</span> <span class="mi">10</span> <span class="n">sphere</span> <span class="n">v_R</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>In this case, the manifold parameter will change in time according to the variable.
|
|
This is not a problem for the time integrator as long as the change of the manifold is slow with respect to the dynamics of the particles.
|
|
Note that if the manifold has to exert work on the particles because of these changes, the total energy might not be conserved.</p>
|
|
</div>
|
|
<hr class="docutils" />
|
|
<div class="section" id="restart-fix-modify-output-run-start-stop-minimize-info">
|
|
<h2>Restart, fix_modify, output, run start/stop, minimize info</h2>
|
|
<p>No information about this fix is written to <a class="reference internal" href="restart.html"><span class="doc">binary restart files</span></a>. None of the <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> options
|
|
are relevant to this fix. No global or per-atom quantities are stored
|
|
by this fix for access by various <a class="reference internal" href="Section_howto.html#howto-15"><span class="std std-ref">output commands</span></a>. No parameter of this fix can
|
|
be used with the <em>start/stop</em> keywords of the <a class="reference internal" href="run.html"><span class="doc">run</span></a> command.
|
|
This fix is not invoked during <a class="reference internal" href="minimize.html"><span class="doc">energy minimization</span></a>.</p>
|
|
</div>
|
|
<hr class="docutils" />
|
|
<div class="section" id="restrictions">
|
|
<h2>Restrictions</h2>
|
|
<p>This fix is part of the USER-MANIFOLD package. It is only enabled if LAMMPS
|
|
was built with that package. See the <a class="reference internal" href="Section_start.html#start-3"><span class="std std-ref">Making LAMMPS</span></a>
|
|
section for more info.</p>
|
|
<p>Only use this with <em>min_style hftn</em> or <em>min_style quickmin</em>. If not, the constraints
|
|
will not be satisfied very well at all. A warning is generated if the <em>min_style</em> is
|
|
incompatible but no error.</p>
|
|
</div>
|
|
<hr class="docutils" />
|
|
<div class="section" id="related-commands">
|
|
<h2>Related commands</h2>
|
|
<p><a class="reference internal" href="fix_nvt_manifold_rattle.html"><span class="doc">fix nvt/manifold/rattle</span></a>, <a class="reference internal" href="fix_manifoldforce.html"><span class="doc">fix manifoldforce</span></a></p>
|
|
<p><strong>Default:</strong> every = 0, tchain = 3</p>
|
|
<hr class="docutils" />
|
|
<p id="andersen"><strong>(Andersen)</strong> Andersen, J. Comp. Phys. 52, 24, (1983).</p>
|
|
<p id="paquay"><strong>(Paquay)</strong> Paquay and Kusters, Biophys. J., 110, ???, (2016), to be published,
|
|
preprint available at <a class="reference external" href="http://arxiv.org/abs/1411.3019/">arXiv:1411.3019</a>.</p>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
<footer>
|
|
|
|
|
|
<hr/>
|
|
|
|
<div role="contentinfo">
|
|
<p>
|
|
© Copyright 2013 Sandia Corporation.
|
|
</p>
|
|
</div>
|
|
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
|
|
|
|
</footer>
|
|
|
|
</div>
|
|
</div>
|
|
|
|
</section>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
var DOCUMENTATION_OPTIONS = {
|
|
URL_ROOT:'./',
|
|
VERSION:'',
|
|
COLLAPSE_INDEX:false,
|
|
FILE_SUFFIX:'.html',
|
|
HAS_SOURCE: true
|
|
};
|
|
</script>
|
|
<script type="text/javascript" src="_static/jquery.js"></script>
|
|
<script type="text/javascript" src="_static/underscore.js"></script>
|
|
<script type="text/javascript" src="_static/doctools.js"></script>
|
|
<script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
|
|
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2/js/jquery-1.11.0.min.js"></script>
|
|
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2/js/lightbox.min.js"></script>
|
|
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2-customize/jquery-noconflict.js"></script>
|
|
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript" src="_static/js/theme.js"></script>
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
jQuery(function () {
|
|
SphinxRtdTheme.StickyNav.enable();
|
|
});
|
|
</script>
|
|
|
|
|
|
</body>
|
|
</html> |